Ullmann-type N-arylation of anilines with alkyl(aryl)sulfonium salts

Abstract

A palladium/copper-cocatalyzed Ullmann-type N-arylation of anilines using alkyl(aryl)sulfonium triflates as arylation reagents has been accomplished. The reaction enabled C_aryl–S bond cleavage over C_alkyl–S bond breakage of alkyl(aryl)sulfoniums by Pd(P(tBu)₃)₂/CuI and gave the corresponding N-arylated products in good to high yields. It was also significant that the reactions of aniline with asymmetric butyl(mesityl)(aryl)sulfonium triflates showed excellent selectivity, in which the aryl groups other than the bulky and electron-rich mesityl moieties were transformed.